<svg xmlns="http://www.w3.org/2000/svg">
  <foreignObject x="0" y="0" width="100px" height="100px">
    <!-- lime background -->
    <div xmlns="http://www.w3.org/1999/xhtml"
         style="background:lime; width:100%; height:100%;">

      <!-- embedded iframe, whose contents shouldn't be shown, when we're
           being viewed as an image -->
      <iframe xmlns="http://www.w3.org/1999/xhtml"
              style="width:80px; height:80px; border: 0"
              src="data:text/html,%3Chtml%3E%3Cbody%20style%3D%22background-color%3A%20red%22%3Eiframe%20contents%3C%2Fbody%3E%3C%2Fhtml%3E"/>
    </div>
  </foreignObject>
</svg>
